files/textFiles/Source.c

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <conio.h>
#include <stdlib.h>
#include <malloc.h>
#include <ctype.h>
#include <math.h>
int is_number(char* str) {
	int dot = 0;
	while (*str) {
		if (*str == '.') {
			dot++;
		}
		else if(!isdigit(*str)&&*str != '-' && *str !='+') {
			return 0;
		}
		str++;
	}
	return (dot <= 1);
}

void read(double* arr) {
	
	FILE* file;
	char p[100];
	double d;
	file = fopen("1.txt", "r");
	FILE* file2;
	file2 = fopen("result.txt", "w");
	int n = 0;
	while ( fscanf(file, "%s", p) != EOF && is_number(p) && n < 3)
	{
		if (n == 0 && atof(p) == 0) {
			fprintf(file2,"Ýòî íå êâàäðàòíîå óðàâíåíèå");
			exit(1);
		}
		d = atof(p);
		
		*arr = d;
		arr++;
		n++;
		

	}
	if (n != 3) 
	{
		fprintf(file2, "Ìàëî äàííûõ èëè îíè íåêîððåêòíûå");
		exit(1);
	}
	fclose(file);

}

void solve(double* arr) {
	double a = *arr++;
	double b = *arr++;
	double c = *arr;
	double d = b * b - 4 * a * c;
	double x1, x2;
	FILE* file;
	file = fopen("result.txt", "w");
	if (d < 0) {
		fprintf(file, "Äèñêðèìèíàíò ðàâåí %.3lf\n", d);
		fprintf(file, "Äåéñòâèòåëüíûõ êîðíåé íåò");
		return 0;
	}
	else if (d > 0) {
		x1 = (-b + sqrt(d)) / (2 * a);
		x2 = (-b - sqrt(d)) / (2 * a);
		fprintf(file, "Äèñêðèìèíàíò ðàâåí %.3lf\n", d);
		fprintf(file, "x1 = %.3lf\nx2 = %.3lf", x1, x2);
		return 0;
	}
	else {
		x1 = (-b) / (2 * a);
		fprintf(file, "Äèñêðèìèíàíò ðàâåí %.3lf\n", d);
		fprintf(file, "x1 = %.3lf\n", x1);
		return 0;
	}

	
}

int main()
{
	system("chcp 1251 < nul");
	double* arr = malloc(3 * sizeof(double));
	read(arr);
	solve(arr);
	return 0;
}